后置处理中平面轮廓拐角加工程序自动生成技术

为解决早期数控程序中没有考虑拐角加工问题，本文提出了围绕NC 代码 识别拐角并自动生成拐角加工数控程序算法，以满足产品升级与加工高要求之需，进一步确 保数控加工安全与零件表面质量。为实现拐角识别，首先总结归纳常见数控代码结构；其次 还原NC 代码的几何形态并采用线链表示，计算线链走向、线链边之切矢；将拐角分为点式 拐角与圆弧式拐角两大类型，综合拐角的离散结构与线链的封闭性，给出了拐角的识别原理 与相应准则。拐角加工按分层铣削加工，从刀具轴向上减少刀具在拐角位置处加工瞬时的切 削量；各层拐角加工刀轨由进刀、切入、拐角加工、切出与退刀五段组成；层间刀轨采用进 退刀连接线衔接。最后用实例验证了该算法的正确性。

Automatic Generation of Corner Machining Program for Planar Profilesduring Post-processing

To solve the problem of early NC programs lack of corner processing, an algorithm about corner recognition and automatical generation of processing program for planar profiles around NC code is proposed. This method can meet the product upgrades and high processing requirements of NC machining, and further ensure the security and the surface quality of parts. Firstly the common NC code structure is summed up. Secondly the NC Code geometry representation is expressed as edge chains. Then the direction of those chains and the edge tangent in chains are computed. And the corners are classed as point and arc corners. At the same time, the recognition rules of corner, considering these factors such as discrete structure of arc corner and closure of chains, are presented. To reduce the instantaneous cutting amount of processing at the corner position from the tool axis, Corner machining is layered. Each layer of corner processing tool path consists of feeding, cutting in, corner processing, cutting out and retracting sections. Layers of path are connected with feeding-retracting lines. Finally, an experimental result is showed to prove this algorithm.